Honestly, though, I'd be happy if the navmeshes were fixed. In Anctoville, for instance, bots trying to go down that main road to the church keep getting stuck behind those walls of sandbags and keep trying to jump over them.
After that, if it could be done to somehow teach bots how to effectively use cover, rather than just walk down the middle of the road and crouch to shoot, that would add a whole new element to SP games.
Also, tanks. Because of the raised POV in the entry position of a tank, the bots can see over things that players wouldn't be able to. Bots will try to shoot you through walls. The most annoying part of it is that sometimes they succeed. If it could somehow be made so that bots don't use the raised view to peek over walls and fire, that would be great.